Wrong - the letter says should you vote yes and go on strike
Since the company cannot know whether you as an individual have voted 'yes' or 'no' this clearly applies in the wider sense.
If, as a group, you vote to strike you each, individually, lose ST.
Hope that clears it up.
Not necessarily. It won't be hard for the company to see who comes into work and who doesn't. Those that don't will presumably be the ones who lose out. BA aren't going to penalise those who make the effort to come in.